The present disclosure relates to a method of introducing ions into a mass spectrometer and an ion inlet device.
The coupling of ionization sources such as Electrospray Ionization (“ESI”) to the vacuum of a mass spectrometer may be done through a differential pumping aperture, such as a capillary or small orifice inlet. Low ion transfer efficiency through the inlet may represent a major bottleneck. Over recent years, for increased sensitivity, the inlet orifice of the mass spectrometer has been enlarged in order to collect and transmit more and more ions into the system. A limitation of increasing the inlet orifice can be the size and cost of the associated pumping system.
An increased inlet flow may lead to significantly increased heater power requirements for a required desolvation temperature. Maintaining the exterior wall of an inlet capillary at a particular temperature can be ineffective at heating the gas within the capillary, for example generating a mixture of solvated and desolvated ions.
US2010/282966 (Schneider) discloses a method and system for a vacuum driven mass spectrometer interface with adjustable resolution and selectivity.
EP0607908 (Visser) discloses a method and apparatus for sampling a reactive atmosphere into a vacuum chamber of an analyser.
WO2013/076307 (Makarov) discloses a high duty cycle ion spectrometer.
It is desired to provide an improved method of introducing ions into a mass spectrometer.